This invention relates to flexible drains of the type used to drain filter and lubricator bowls.
Certain types of filtration and lubrication devices consist of cartridge type filters in an air or lubricant supply line. These filters frequently consist of a removable filter cartridge within a filter container. The filter container frequently has two components: a cap secured in the air or lubricant supply line, and a bowl removably securing the filter within the cap.
After filtration by the cartridge filter, contaminants settle at the bottom of the bowl. The contaminants must be drained from the bottom of the bowl intermittently to allow the filter to operate effectively. The problem is to provide a drain that reliably seals the bowl when not draining and yet allows an operator to quickly drain the bowl without removing the bowl and with minimum effort whenever desired, and even when the filter is located is very difficult to reach areas.
One type of bowl drain known in the art is a flexible drain. The flexible drain penetrates the bottom of the bowl and includes an internal valve that drains the bowl when the flexible drain is pushed sideways, off of its free state vertical axis. Wilkerson Corporation of Englewood, Colorado makes such a product known as a FLEX-DRAIN. It includes rubber tube passage from the bottom of the bowl with a brass valve member positioned in the passage. The valve member is comprised of spaced disc members connected by an axial stem. One disc seals against one end of the rubber tube passage. The other disc engages the side walls of the passage to insure axial alignment. Squeezing and flexing the tube opens the passage.
A problem with these prior art flexible drains is that, although they may effectively drain the bowls, they do not effectively maintain a seal when the filter is in use. Especially when the pressure within the bowl is low, such as between 0 and 15 p.s.i., the valves in the prior art flex drains after are not closed effectively enough to provide a secure seal at all times when not being used to drain the bowls.
It is thus an object of the present invention to provide a flexible drain that effectively seals filter bowls even at low pressures.
Yet another object is to provide such a drain that is economical and easy to use.
A further object is to provide a flexible drain consisting of a minimum number of components: a flexible drain body, a rigid valve, and additionally but not necessarily, a sealing washer.
An additional object is to provide such a flexible drain that is easily replaceable as the old flexible drain becomes worn or fatigued through use.
There are further objects and advantages that will become apparent as the specification proceeds.